1. Field of the Invention
The invention relates to an input device.
2. Description of the Related Art
An input device is known that a false detection is prevented by measuring time for charging electrodes on a capacitive touch panel and time for discharging them (see, e.g., JP-A-2011-076515).
The input device has plural pairs of electrodes two-dimensionally arranged in a touch detection area, a selection circuit sequentially selecting each of the plural pairs of electrodes, a charge circuit for charging a pair of electrodes selected by the selection circuit, a charge time measuring circuit for measuring charge time from when the charge circuit starts charging the pair of electrodes until reaching a predetermined upper threshold, a discharge circuit for discharging the pair of charged electrodes and a discharge time measuring circuit for measuring discharge time from when the discharge circuit starts discharging the pair of electrodes charged to the predetermined upper threshold until reaching a predetermined lower threshold, and the input device determines, based on a ratio of the charge time to the discharge time, whether contact of a touch object in a touch area is detected or it is false detection.